electronics help

Started by unknown · date unknown · 7 posts

1. Dankie

   #1 · date not recorded

   So I have 50 % duty cycle signal that is driving an and gate , this signal is phase locked to another frequency via a frequency divider . This "other" faster frequency is always 50% duty cycle and that will never change
   
   What I wish to do is control the duty cycle of this normally 50/50 duty cycle frequency . It will be opreating in the ranges of 1khz to 50 khz
   
   I wish to control the duty cycle from a range to 0 to 100% so I can drive my and gate with this signal .
   
   I am just not smart enough to figure out how I should do this , somebody plz help me .
   
   
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   qpulse.JPG

2. Radiant_1

   #2 · date not recorded

   If the signal is a function of the "other" faster frequency which is always a 50% square wave....just slowed down by a frequency divider, you will not be able to adjust the duty cycle w/o adjusting the "other" frequencies' duty cycle
   
   I suggest you use a cd4047 in the "compliment gating" mode....and use a 555 timer to the gate pin. Just make it so both circuits are in parallel (common electrodes) and have the output of the 555 go through a large resistor (1-2 Mohms) and an LED (if LED lights up the signal is too high of a voltage)
   
   To change the gating duty cycle all you have to do is make r1/r2 variable resistors and you can change them independently to make any duty cycle u wish!
   http://i175.photobucket.com/albums/w152/Jdub6d9/555ast.gif

3. Dankie

   #3 · date not recorded

   god dammit
   
   I cant believe there is not some sort of IC that can do this

4. Radiant_1

   #4 · date not recorded

   There maybe...however, every IC chip ur signal goes through lags/degrades the signal more and more.

5. Dankie

   #5 · 31 May 2009

   haha I decided to drop this idea
   
   I will only use mutiples of the frequency , either divided by 4 or 8 .

6. Dankie

   #6 · date not recorded

   its getting there , let me offer you a discount on a new pwm lol .
   
   All my wire customers will .

7. urizan

   #7 · date not recorded

   Quote from: Dankie on June 05, 2009, 16:46:36 pm

   its getting there , let me offer you a discount on a new pwm lol .
   
   All my wire customers will .
   

   
   awesomeness